External heart massage apparatus

ABSTRACT

An external heart massage apparatus having of a generally Ushaped frame which is detachably connected to either a base member or by means of adaptor clamps to the side rails of a stretcher, operating table, or the like. A plunger is reciprocally mounted on the frame, and a lever is operatively associated with the plunger whereby the displacement of the lever effects reciprocation of the plunger to impart the requisite external massage on the heart of a patient. Axial transmission of the force between the lever and the plunger is attained by a rolling type cam which is connected to the upper end of the plunger so as to be disposed in rolling engagement with the lever.

United States Patent Gaquer et a1.

EXTERNAL HEART MASSAGE APPARATUS Inventors: George E. Gaquer, 22 Taber Place,

Nutley, NJ. 07010; John Gaquer, 14 Bromley Place, Bloomfield, NJ. 07003; Alphonse Nagourney, 334 Unity Road, Trumbull, Conn.

Filed: Dec. 29, 1911 Appl. No.: 213,313

[52] 11.8. C1. 128/51 [51] Int. Cl. A6lh 7/00 [58] Field of Search 128/28, 51, 52, 53

[56] References Cited UNITED STATES PATENTS 3,489,140 1/1970 Mullikin 128/51 1,918,546 7/1933 Johnson 128/28 3,219,031 11/1965 Rentsch 128/51 3,277,887 10/1966 Thomas .21.. 128/53 3,425,409 2/1969 Isaacson 128/28 Primary ExaminerLawrence W. Trapp AttorneyArthur T. Fattibene [57] ABSTRACT An external heart massage apparatus having of a generally U-shaped frame which is detachably connected to either a base member or by means of adaptor clamps to the side rails of a stretcher, operating table, or the like. A plunger is reciprocally mounted on the frame, and a lever is operatively associated with the plunger whereby the displacement of the lever effects reciprocation of the plunger to impart the requisite external massage on the heart of a patient. Axial transmission of the force between the lever and the plunger is attained by a rolling type cam which is connected to the upper end of the plunger so as to be disposed in rolling engagement with the lever.

28 Claims, 23 Drawing Figures 6 Sheets-Sheet 1 22A f INVENTOR Game: 4- anausx 6. awn/5R F/ 2 BY A w mwpukusy Patented June 19, 1973 3,739,771

3/ I 28 F/G 6 Patented June 19, 1973 G Sheets-Sheet 3 Patented June 19, 1973- 3,739,771

6 Sheets-Sheet 4 Patented June 19, 1973 6 Sheets-Sheet 5 7A 7/3 F/G /2 Patented June 19, 1973 6 Sheets-Sheet 6 MIA 1 EXTERNAL HEART MASSAGE APPARATUS PROBLEM AND PRIOR ART External heart massage has become a common practice among medical practitioners and it constitutes a widely adopted and recognized resuscitation procedure. However, the heart massage resuscitation procedure has been generally limited to those who have attained a high degree of competency. This high degree of competency was required to avoid injury to the patient and necessary to achieve maximum effectiveness. In many instances, particularly during an emergency, external heart massage was manually performed. When manually performed the problem of sufiicient strength and fatigue on the part of the operator become criticalfactors as to whether or not the massage will be sufficiently effective to revive a patient. To thus facilitate external heart massage various mechanical devices have been conceived for applying the necessary pressure and rhythm to the sternum or chest cavity. However, most of the known devices are costly and elaborate, and for these reasons are generally confined to medical establishments such as hospitals, emergency rooms, etc.

Because of this, the need has arisen for the development of a relatively simple, low cost unit which can be readily portable and rendered readily available to a doctor, first aider, police department, fire department, etc.

It has also been noted that the application of external heart massage is frequently required while a patient is lying on a'stretcher, as for example, when riding in an ambulance, or lying on an operating table during a surgical operation. In such instances it may be extremely difficult to position the base board behind the patient, as movement of the patient may be critical. This problem becomes especially aggravated during certain operative procedures where any movement of the patient is prohibitive. In such situations the construction of the Rentsch apparatus would render it ineffective, as such apparatus could only be effectively used when the base member was disposed behind the back of the patient.

Thus if the base member of the Rentsch device could not be positioned behind the patient, because the patient could not be moved, it would be rendered useless. Also the patented construction did not realize maximum efficiency of mechanical advantage.

OBJECTS It is therefore an object of this invention to provide an improved external heart massage apparatus which is relatively simple in construction, positive in operation and which can be inexpensively manufactured.

Another object of this invention is to provide an improved external heart massage apparatus in which maximum utilization of mechanical advantage can be achieved so as to minimize any resulting fatigue on the part of an operator during long and tiring resuscitation procedures.

Another object of this invention resides in an external heart massage having an, improved transmission means for imparting the requisite force necessary to effect the displacement of the chest cavity for maximum resuscitation efforts.

Another object is to provide an improved external heart massage apparatus in which the resulting depression of a chest cavity can be controlled or adjusted from patient to patient.

Another object of this invention is to provide an external heart massage apparatus with adjustments by which an operator can effectively control the displacement required of a chest cavity between minimum and maximum limits.

Another object of this invention resides in the provision of an external heart massage apparatus which can be readily knocked down between an operative, operating position and an inoperative stowed position.

Another object of this invention resides in the provision of an external heart massage apparatus which can be rendered readily adapted for use while a patient is lying on a stretcher or operating table when any movement of the patient is prohibited.

BRIEF SUMMARY OF THE INVENTION The foregoing objects and other features and advantages of the invention are attained by an external heart massage apparatus which comprises of a frame defined as a substantially inverted U-shaped member on which a plunger means is mounted for reciprocal movement toward and away from the chest cavity of a patient to impart the requisite massage on a patients heart. An operating lever is pivotally connected to the frame and is operatively associated with the plunger for effecting the reciprocation thereof when the lever is actuated. An improved transmission means is interposed between the lever and the plunger means whereby a force imparted by the lever is transmitted axially to the plunger as the lever means is actuated.

The improved transmission means between the lever and the plunger comprises cam transmission, e.g. a cam roller or rocking cam connected to one of the members so as to be disposed in rolling engagement with the other resulting in a rolling camming action therebetween. The arrangement is such that the force of the lever is transmitted axially to the plunger as the lever is actuated. In one embodiment the cam roller includes a flanged guide which is operatively associated with a guide follower to maintain the connection between the lever and the plunger means throughout the stroke thereof. The external heart massage apparatus includes a supporting means either in the form of a base member which is placed under a supine patient for supporting the frame over the supine patient or as adaptors clamped to the side rails of a stretcher, operating table or the like. In either event the base member or adaptors are provided with socket means by which the leg members of the frame may be detachably secured. The socket means when associated with the base member include means by which the base member may be stowed on the frame of the apparatus in the inoperative position.

The socket means when utilized on the adaptors are rendered laterally adjustable so that the frame of the heart massage apparatus can be readily adapted to stretchers or operating tables of varying widths within a predetermined range of widths.

Means are also provided for controlling the stroke of the lever means and/or adjustment of the plunger between minimum and maximum limits.

FEATURES A feature of this invention resides in the provision of an improved external heart massage apparatus having an improved transmission means interposed between the lever and the plunger to insure maximum efficiency of axial force transmission between the lever and the plunger means.

Another feature of this invention resides in the provision of an external heart massage apparatus in which the mechanical advantage thereof is enhanced to minimize fatigue on the part of the operator during long resuscitation procedures.

Another feature of this invention resides in an external heart massage apparatus having means for controlling the stroke of the lever between minimum and maximum limits.

Another feature of this invention resides in the provision of adaptors by which the frame portion of the external heart massage apparatus can be supported relative to a patient lying on a stretcher or operating table.

Another feature of this invention resides in the provision of a heart massage apparatus in which the supporting base member of the apparatus can be stowed directly to the frame of the apparatus in the knockeddown or inoperative position thereof.

Another feature of this invention resides in the provision of a heart massage apparatus having improved latching means for detachably securing the legs of the frame to its supporting means.

Another feature of this invention resides in the provision of a first stop means for controlling the displacement of the lever between minimum and maximum limits and second stop means for controlling the displacement of the lever intermediate the minimum and maximum limits.

Another feature of the invention resides in the provision of a heart massage apparatus which can be equally operated by either a left handed or a right handed person.

Other features and advantages of this invention will become more readily apparent when considered in view of the drawings and description in which:

FIG. 1 illustrates a perspective view of the heart massage apparatus embodying the present invention shown in its operative position.

FIG. 2 is a front elevation view of the external heart massage apparatus of FIG. 1 illustrated in an inoperative, stowed position.

FIG. 3 is a perspective view illustrating the apparatus of FIGS. 1 and 2 as applied to a supine patient.

FIG. 4 is an enlarged fragmentary sectional elevation view of the force transmission means between the operating lever and the plunger illustrated in its normal retracted position.

FIG. 5 is a sectional view similar to that of FIG. 4 but illustrating the respective parts in an operative depressed position.

FIG. 5A is a sectional view taken along line 5A--5A on FIG. 5.

FIG. 6 is an enlarged detailed sectional view illustrating the detachable latching means between the frame and its base member.

FIG. 7 is a bottom plan view taken along line 7-7 on FIG. 6.

FIG. 8 is a detailed front elevation view illustrating the transmission means between the lever and the plunger.

FIG. 9 is a detailed sectional view taken along line 9-9 on FIG. 8.

FIG. 10 is a perspective view of a detail of a modified plunger construction.

FIG. 1 1 is a perspective view of the heart massage apparatus of the present invention utilized in conjunction with an operating table.

FIG. 12 is a sectional view of the adaptor utilized for supporting the frame of the external heart massage apparatus to the side rails of an operating table.

FIG. 13 is a perspective view illustrating the manner in which the heart massage apparatus may be applied to an ambulance stretcher.

FIG. 14 is a detail of construction illustrating the adaptor means of FIG. 13.

FIG. 15 is a modified construction of an adaptor means.

FIG. 16 is a detailed section of a modified force transmission means between the operating lever and the plunger.

FIG. 17 is a fragmentary detail of a modified construction for effecting the limit adjustments of the operating handle.

FIG. 18 is a detailed sectional view of a modified construction of a force transmission member between the operating lever and the plunger.

FIG. 19 is a view similar to that of FIG. 18, but showing the parts in an operative depressed position.

FIG. 20 is a detail of another modified limit adjustment to control the effective displacement of the operating lever.

FIG. 21 is a selected detail view of another modified adjustable stop means to limit the stroke of the plunger adapted for use on an external heart massage apparatus of the type disclosed.

FIG. 22 is a plan view taken along line 22-22 on FIG. 21.

Referring to the drawings, there is shown in FIGS. 1-3 a heart massage apparatus 20 embodying the present invention. The apparatus 20 comprises a frame 21 which, as illustrated in FIGS. 1 and 2, comprises a substantially inverted, U-shaped member having opposed leg portions 21A-21A and an interconnecting bight portion 21B. In one form of the invention the frame 21 is detachably connected to a support means in the form of a flat base member 22 which is arranged to extend under the body of a supine patient, as seen in FIG. 3.

The base member 22 is provided with socket means 23 for detachably receiving the lower end portion of the respective leg portions 21A, 21A. Referring to FIGS. 6 and 7 the respective socket means 23 comprises a cup-shaped member 24 having its bottom wall 25 having a laterally extending circumscribing flange portion 25A. The socket means 23 is embedded or secured to the base member 22 in an appropriate opening 26 provided therefor. The internal wall of the cupshaped member 24 is formed with a circumscribing latching groove 27.

The respective leg portions 21A, 21A of the frame 21 are each provided with a latching means 28 by which the legs of the frame are detachably secured to the respective sockets 23 in the operative position thereof. As best seen in FIG. 6 the latching means 28 comprises a leaf spring 28A which is suitably secured at one end to an internal portion of the frame leg 21A. Connected to the free end of the leaf spring 28A is a catch 29 which is adapted to extend through a catch opening 30 formed in leg 21A. The arrangement is such that the leaf spring 28A normally biases the catch 29 through the catch opening 30. A latch button 31 is connected to an intermediate portion of the leaf spring 28A, and it extends through an opening 32 spaced above the catch opening 30. The arrangement is such that by depressing the latch button 31, a force is applied against the bias of the spring 28A to effect the retraction of the catch 29.

In operation the legs 21A, 21A of the frame member 21 are secured to the respective sockets 23 of the base member 22 by simply inserting the legs thereinto. In

doing so catch 29 will engage and latch with angular groove 27 and thereby support the frame 21 in erected position on the base member 22. To separate the frame 21 from its base 22, an operator simply depresses the latching button 31 causing the latch spring to depress and disenage the catch 29 from its locking groove 27. To facilitate self-latching of the catch 29 when the respective legs 21A are positioned in the respective sockets, the sockets are formed with an inclined surface 23A circumscribing the opening thereof. The inclined surface functions to automatically cam the catch 29 inwardly of the respective leg portions as the leg 21A is inserted into the socket. When the catch 29 has moved into alignment with the latching groove 27, the bias of the spring 28A will force the catch in groove 27 to effect automatic engagement of the catch within the groove.

As seen in FIG. 2 the base member 22 may be stowed onto the frame 21 of the heart massage apparatus in the knocked-down or inoperative position thereof. This is attained by providing an opening 34 formed in the bottom wall of the socket 23 by which the base 22 is supported. A headed fastener 35 is secured to the leg portions 21A, 21A of the frame 21. To stow the base member 22 when the apparatus 20 is not in use, the base member 22 is supported directly on the frame members by extending fasteners 25 through the opening 34 formed in the bottom wall 25 of the socket. The base 22 is removed by raising the base slightly so that the head portion of the fastener is brought into alignment with the enlarged center of hole 34 whereby the base can be readily removed from the frame.

Connected to the bight portion 21B of the frame is a plunger sleeve mount 36. As best seen in FIGS. 4 and 5, the lower end of the plunger sleeve mount has an intumed flange 36A which defines an opening 37 and a bottom support for a coil spring 38. A tubular plunger sleeve 40 is supported within the plunger mounting sleeve 36, for reciprocal movement therein. Also the sleeve 40 may be rotated within the sleeve whereby the apparatus may be readily adapted for either right hand or left hand operation.

As shown in FIGS. 4 and 5 the plunger sleeve 40 has secured intermediate the-ends thereof a collar 41 to define an abutment against which the coil spring 38 seats. Disposed in the lower end of the plunger sleeve 40 is an insert 42 having an opening 42A shaped to complement the cross-sectional shape of an elongated plunger rod 43. Preferably the insert opening 42A is provided with at least one flat edge to permit orientation of the plunger rod 43 with respect thereto. In the illustrated form of the invention the plunger rod 42 is formed with a substantially rectangular cross section to complement a rectangular opening 42A formed in the insert '42. By orientating the plunger rod relative to the tubular plunger sleeve 40, the plunger can be maintained in alignment with the sternum of the patient. In the construction described the plunger rod 43 may be vertically adjusted within the plunger sleeve 40 as indicated in FIG. 4. Adjustment of the plunger rod is provided to locate the pressure pad 44 connected to the end of the plunger rod, to the chest cavity of a patient. As patients vary in size the plunger rod adjustment enables the apparatus 20 to be adjusted to a particular patient. The plunger rod 43 is secured in adjusted position by a collar 45 secured to the sleeve 40 by a set screw 46. The collar is provided with a tapped hole 45A for receiving the screw 46, and it is disposed in alignment with an opening 47 formed in insert 42. With the screw 46 disposed in alignment with opening 47, it will be noted that by tightening screw 46, the plunger rod 43 is secured in adjusted position.

The plunger sleeve 40 is arranged so that the upper end thereof will normally extend above the end of the plunger mounting sleeve 36. As best seen in FIGS. 4, 5, 8 and 9 the upper end of the sleeve 40 is bifurcated or slotted at 48, and flanged transmission means in the form of a cam roller 49 is rotatably journalled by pin 50 in the upper end of the sleeve 40. As best seen in FIGS. 4, 5, 8 and 9 the roller 49 is supported within the sleeve 40 so that a peripheral portion thereof extends beyond the end of the sleeve 40. The roller 49 is rotatably journalled between opposed portions of the sleeve by a'pin 50 about which the roller is free to rotate.

Intermediate the width of roller 49 there is provided a projecting flange guide 51 which is adapted to be received within a guide follower, e.g., a slotted opening 52 formed in operating lever 53.

The operating lever 53 provides the means by which the plunger means is actuated. One end of the lever is pivotally connected at a fulcrum 54 located on the bight portion of the frame intermediate the ends. The locations of the fulcrum and the length of the lever 53 is determined to provide a mechanical advantage of approximately 4 to l.

A first stop means in the form of a U-shaped bracket 55 is connected to the leg portion adjacent the free end 53A of lever 53. The bracket for receiving the free end 53A of lever 53 defines the minimum and maximum displacement of the lever 53. The arrangement is such that the depressed position of the operating lever 53 is limited by abutment of the lever 53 against the adjacent leg portion 21A of the frame. In the normal position of the lever it is limited by the end of the U-shaped portion of bracket 55.v The bracket 55 thus defines the maximum and minimum range of movement of lever 53.

With the transmission means described in the form of a roller cam 50 disposed in rolling engagement with the lever 53 the arrangement is such that whenever the lever 53 is actuated, an axial force is transmitted to the plunger rod 43 and associated compression pad 44. With this construction any binding which would otherwise occur between the plunger mount 36 and sleeve 40 upon the actuation of the lever is minimized. This is because the component force transmitted to the plunger sleeve is maintained axially of the plunger in all positions of the operating lever.

In certain instances it may be desirable to provide a second stop means to limit the amount of vertical displacement of the plunger to a distance intermediate the minimum and maximum depression of the operating handle. Such adjustment is necessitated as a result of a patients size and/or weight. This adjustment is attained by providing an adjustable stop collar 57 about the upper end or extended portion of the plunger sleeve 40. As best seen in FIGS. 4 and 5 the collar is slidably mounted on sleeve 40 whereby it can be vertically adjusted about the sleeve. A set screw 58 is suitably threaded into a tapped opening 59 formed in the collar 57 for securing the collar 57 in the adjusted position thereof. Vertical displacement of the plunger means 40 is thus controlled by the abutment of the stop collar 57 against the upper end 36A of the plunger mount 36 when the lever 53 is actuated. Normal resuscitation procedure requires a plunger displacement of approximately 2 inches. However, depending upon the physical characteristics of a patient, i.e., size, weight, bone structure, etc., more or less displacement of the plunger may be required. For this reason the adjustable collar or stop 57 can be readily adjusted to the extended end of plunger sleeve 40 so that the displacement of the plunger may be controlled at any optimum position between the minimum and maximum range of lever movement.

FIG. 17 illustrates a modified embodiment 90 similar to the embodiment described with respect to FIG. 1 except that the stop means 91 to limit or adjust the amount of vertical displacement of the plunger necessitated by a patients variable physical proportions is modified. As best seen in FIG. 17, the secondary stop means 91 comprises a series of openings 92 located in the bracket 55' connected to the leg portion 21A of the frame means 21. A stop pin 93 is adapted to be inserted into one of the openings so that the movement of the operating lever 53 will be limited between the end of the bracket 55' and the hole in which the stop pin 93 is located. The holes 92 in the bracket 55' are spaced so that the lever 53 may be adjustably displaced in a range from 1 to 3 inches, preferably 1% to 2% inches.

FIG. illustrates another modified construction of a secondary stop means 100 which may be utilized to limit the vertical displacement of the plunger depending upon the physical proportions of a particular patient. In this form the modified secondary stop means 100 comprises a vertical slot 101 formed in the upper end of the plunger member 40 that extends above the plunger mount 36. Connected into communication with a vertical slot portion 101A are a plurality of laterally extending branch slots 1018 which are horizontally spaced. The spacing of the horizontal slots 1013, as will be described, determines the fixed limit of displacement of the plunger.

Cooperatively associated with the slot 101 is a stop collar 102 which circumscribes the slotted portion of the plunger 40. The arrangement is such that the collar can be infinitely adjusted within the range of the vertical slot portion 101A adjusted to a predetermined set position as defined by the horizontal slot 101B by imparting a slight angular rotation to the collar 102 to effect alignment of the set screw 103 within one of the laterally extending branch slots 1018. With the stop configuration of FIG. 20 it will be noted that the stop collar 103 can be infinitely adjusted along the vertical portion 101A of the slot 101 or fixed at a predetermined setting as determined by one of the branch slots 101 B.

In the illustrated form of FIG. 20 the lower horizontal slot 1018 is arranged so as to limitthe stroke of the plunger means to 1% inches. The middle lateral slot will limit the displacement of the stroke to 2 inches and the upper slot limits the displacement of the plunger to 2% inches. Infinite intermediate settings may be accomplished by adjusting the stop collar 102 along the vertical portion 101A of the slot. With this arrangement it will be apparent that the stop collar 102 may be set at any of a predetermined fixed settings by the horizontal slot portions and at an infinite number of intermediate settings within the range of the vertical slot portion 101A.

FIGS. 21 and 22 illustrate another modified embodiment of a secondary stop means adapted for use on the heart massage apparatus disclosed. As shown therein the stop means 120 comprises a collar 121 which is vertically slidable on the upper end of plunger sleeve 408. To prevent rotation of the collar 121 relative to sleeve 40B the latter is provided with a key 122 which is adapted to be received in a keyway 123 formed in the collar 121. Formed in the sleeve are a plurality of vertically spaced apertures 127 for adjustably positioning the collar 121 along the sleeve 40B.

Formed in the collar 121 is a bore for receiving a lock pin 125. A spring 126 disposed within a tubular extension 124 normally biases the pin 125 into locking position. It will be understood that the spring 126 is normally urged against a suitable stop on the pin to exert a force in the locking direction. Thus when the pin 126 is aligned with one of the apertures 127, the end of the pin 126 is projected therethrough to fix the collar 121 in the adjusted position. Depending on the adjustable setting of the collar 121, the displacement of the plunger may be either 1%, 2 or 2% inches. However, it will be understood that additional settings may be provided by the inclusion of additional apertures 127.

In the embodiment of FIGS. 1-5 a compression or pressure pad 44 in the form of a hemispherical ball or bulb formed of a resilient material, as for example, rubber, plastic, etc., is suitably connected to the end of the plunger rod, e.g., by a threaded connection therebetween.

In a modified form of the invention, as illustrated in FIG. 10, the compression member 44A comprises a substantially rectangular member having a convex or rounded bottom and having its longer axis adapted to be directed longitudinally of the patients chest. Also the pad 44A is pivotally connected to its plunger rod 61. The pivotal connection comprises a lug 62 suitably connected to the pad 44A. The lug 62 is pivotally connected to the rod 61 by a pivot pin 63. By pivotally connecting the pad 44A to its plunger rod 61, the arrangement is such that the compression pad is free to pivot enabling it to conform to the contour of a patients chest cavity as the plunger is depressed during the operation of the device. The plunger rod 61 formed with at least one flat surface also insures proper orientation of the axis of the compression pad 44A with the center line of a patients chest.

In operation, the flat base member 22 is slipped under the back of the supine patient. To facilitate the positioning of the base member 22 behind the back of a patient, the end portions of the base member may be tapered as at 22A to permit it to be slipped under the back of the patient. The frame 21 is then fitted to the base member 22 by inserting the respective leg portions 21A, 21A into the base sockets 23 whereby the catch 29 of latching means 28 automatically engages with latching groove 27 to lock the frame in position over the body of a supine patient. The plunger rod 43 is then adjusted within its sleeve 40 to position the compres sion pad 44 in contact with the sternum area of a supine patient. The plunger rod 43 is then secured in position by the fastening set screw 46.

With the compression pad 44 fixed in its adjusted position in contact with the sternum of the patient, the operating lever 53 is pushed downwardly causing the plunger means 40 and associated compression pad 44 to be displaced downwardly and accordingly to depress the sternum of the patient. Depending upon the physical structure and size of the patient, the amount of vertical displacement of the plunger can be further controlled by the operator by setting the stop collar 57 and fixing the same in its adjusted position. With the adjustment made, the operator can continue the resuscitation procedure being assured that each stroke of the lever will effect uniform depression of the patients chest. As the resuscitation process continues the degree of depression of the chest cavity can be varied more or less, depending upon the effectiveness of the procedure by readjusting the stop collar 57. Upon release of the lever 53 after each act of depression, the bias of spring 38 returns the plunger to its initial position. The operation of the massage apparatus is operated in a rhythmic sequence in a manner known to those skilled in applying resuscitation techniques.

In operation the displacement of the lever 53 transmits an axial force to the plunger means as the latter is displaced accordingly, through the rolling camming action of the cam roller 50 and the lever. Since the displacement of lever 53 is controlled by bracket 55, the arrangement is such that the flange guide riding in follower slot 52 insures operative interconnection between the plunger means and lever throughout the displacement limits of the lever.

Upon completion of the resuscitation process the frame member 21 can be readily removed from the patient by depressing the latching buttons 31 on the respective leg portions 21A, 21A and lifting the frame 21 from the base member 22.

In many instances when a patient has been placed, for example, on an ambulance stretcher 80 or when a patient is lying on an operating table 70 undergoing an operative procedure, heart arrest may occur. In such situations it may not be possible or feasible to position the flat base member 22 under the patient. For this reason it may become, necessary to utilize only the frame portion 21 of the massage apparatus. In such event adaptors 71, 81 are provided whereby the frame 21 of the massage apparatus described may be utilized in conjunction with eitheran operating table 70, anambulance stretcher 80, or the like.

As best seen in FIG. 11 an operating table 70 is generally provided with side rails 70A for accommodating various operating appliances generally employed during an operative procedure. In accordance with this invention an adaptor means 71 is provided for specifically accommodating the frame structure 21 of the heart massage apparatus to to the table 70 should such be required. Referring to FIG. 12 the adaptor 71 comprises a pair of block members 71A, 718 which are suitably connected together, as for example by a hinge link 72 which is pivotally connected to the respective blocks 71A, 7118. Each block member 71A, 71B is provided with a complementary notch to define in the operative position thereof, a slot 73 adapted to receive the side rail 70A. In the operative position, the respective blocks 71A, 71B are clamped to the side rail and secured in position by means of a locking screw 74. As best seen in FIG. 12, one end 74A of the locking screw 74 is pivotally connected to block member 718. The complementary block 71A is provided with a bifurcated end portion adapted to receive the screw, and a wing nut 75 is suitably secured to the end of the screw for locking the blocks in assembled position.

The upper block 71B is provided with a dovetailed slot 76 for slidably receiving a slide block 77. In the slide block there is provided a socket 78 for receiving the leg portion 21A of the frame 21. The arrangement is such that the slide block may be moved transversely of the clamping blocks 71, to permit limited lateral movement of the slide block. As operating tables are generally formed of varying widths, the lateral movement afforded between the slide block 77 and the clampling block 71 enables the frame 21 of the heart massage apparatus to be readily accommodated to operating tables of varying widths. The socket 78 is sized to received the leg portion of the frame, and it is formed with an internal latching groove 79 similar to that described with respect to the socket 23 of the base member 22. The limits of lateral movement of the slide block 77 relative to the clamping block 71 is afforded by an elongated groove 71C formed in block member 718 adapted to receive a limiting pin 77A projecting through the slide block 77. Thus, as best seen in FIG. 12, the slide block 77 may be adjusted laterally of the clamping block 71 by the movement permitted by the pin 77A and slot 71C. Thus the standard frame construction 21 of the heart massage apparatus as described in FIGS. 1-5 may be readily adapted to operating tables of varying widths simply by setting the opposed slide blocks 77 of adaptors 71A a distance sufficient to accommodate the leg portions 21A, 21A of frame 21.

FIG. 14 illustrates a modified adaptor 81 for positioning a frame construction 21 of the heart massage apparatus 20 to a stretcher 80, as for example, an ambulance stretcher. Generally such stretchers are formed of round tubular members, as shown. The adaptor construction 81 of FIG. 14 is similar to that described with respect to FIGS. 11 and 12, with the exception that the complementary clamping blocks 81A, 81B are provided with cut-out portions to define a round opening 82 sized for clamping the tubular member A of a stretcher frame. Thus as seen in FIG. 13, the adaptors 81 are secured to the head portion 808 of the stretcher so that the heart massage frame 21 described can be readily secured thereto.

In all other respects the construction and operation of adaptor 81 is similar to that described with respect to FIG. 12. v

FIG. 15 illustrates a slightly modified adaptor 83. In this form of the invention the adaptor 83 is similar to the adaptor 21 described in FIG. 14 with the exception that the clamping blocks 83A and 83B are not hinged together. In this form of the invention it will be noted that clamping blocks 83A and 83B constitute independent components wich are adapted to be detachably secured by means of screw fasteners 84 and associated wing nuts. The screw fasteners or studs 84 are threaded into one of the members, e.g. 83A whereby the other member 838 is provided with aligned bores 85 adapted to be received on the studs, and secured thereto by a wing nut 84A.

Also in this form of the invention the complementary opening portions 86 may be provided with a cut-out portion so that the adaptor may be readily clamped onto either round frame members, or to angular frame members as indicated in the broken line showing in FIG. 16.

In all other respects the adaptor block of FIG. 15 is similar to that described with respect to FIG. 14.

FIG. 16 illustrates a modified form of the invention. In this form the heart massage apparatus 120 is similar to that described and disclosed by FIG. 1 with the exception of a modified transmission means 121. As shown, the transmission means 121 comprises a roller cam 122 which is rotatably journalled to the upper reduced end portion of the plunger 40A. To accommodate the roller cam 122 the upper end of the plunger 40A is bifurcated. The arrangement is such that the roller cam 122 is adapted to be received in a slotted opening 123 formed in the bottom of the hollow lever arm 53. As the roller cam 122 is disposed in rolling engagement with the internal wall of the lever arm 53, it will be noted that as the lever arm is actuated the camming action between the roller 122 and the arm 53 is such that the force applied to the end of the plunger is axially transmitted through the roller cam 122. It will be understood that a secondary stop means of the type herein described may be utilized to limit the effective displacement of the plunger. In all other respects the operation and function of the apparatus 120 of FIG. 16 is similar to that herein described.

FIGS. 18 and 19 illustrate another embodiment of the apparatus having a modified transmission means 1 10 between the operating lever 53 and the plunger 40. As best seen in FIGS. 18 and 19 the apparatus 109 is similar to that herein described with the exception that the upper end of the plunger has connected thereto a rocker arm 111 which is pivotally connected to the plunger 40 by a pivot pin 112. As shown, the rocker arm 111 is provided with an arcuate sector 111A which extends through a slot 112 formed in the tubular lever arm 53 with the arcuate sector 111A disposed in camming or rolling relationship with the internal surface of the lever arm 53. As best seen in FIGS. 18 and 19 the arcuate sector 111A is provided with a length L which is greater than the length of the slot 112. To assemble the arcuate sector 111A within the lever arm, the arcuate sector is obliquely inserted through the slot 112. Once the component parts are disposed in assembled relationship, the arrangement is such that the lever arm 53 is positively connected to the arcuate sector 111A, in a manner which prohibits unintentional or accidental separation of the lever arm 53 from the plunger means and connected arcuate sector 111A.

In operation actuation of the lever arm 53 is such that the plunger 40 is reciprocally moved by the transmission of the force being axially applied thereto.

In this form of the invention a secondary stop means 115 in the form of a stop collar 116 is located on the upper end of the plunger 40. Formed in the plunger 40 are a pluraltiy of detents 116A arranged to cooperate with a spring loaded detent catch 1 17 whereby the stop collar 1 16 may be vertically adjusted along the plunger to limit the displacement of the plunger 40 upon the actuation of the lever arm 53. A set screw 118, arranged to ride in a vertical slot 119 formed in the plunger, is utilized to fixedly secure the stop collar 116 in the adjusted position. The particular detent 116A at which 5 lar 116 may be adjusted and secured to effect a desired displacement, e.g., 1%, 2, or 2%inches; the lowermost detent 116A effecting the lower limit of displacement and the uppermost detent effecting the upper limit of displacement.

10 In all other respects the construction and operation of the apparatus of FIGS. 18 and 19 are similar to that described with respect to FIGS. 1-5.

The heart massage apparatus described thus provides a versatile apparatus which can be used with or without 15 its base member 22. By use of adaptors 71, 81 or 83 it can be readily supportd on a stretcher or operating table. Also the apparatus 20 is provided with a stop which limits the minimum and maximum displacement of the lever, and an indetermined stop to control or limit the displacement of the plunger means within the displacement limits of the lever. Also the transmission interposed between the lever and plunger insures axial transmission of force in a manner which insures an operation free of binding. The apparatus 20 is versatile in that it can be operated either by a predominantly left or right handed person. This is rendered possible because the plunger sleeve 40 can be rotated within the sleeve mount 36 so that the adjustment knobs of set screws 46 and 59 can be located to either side of the apparatus so that the adjustment can be made with either hand depending on the hand dexterity of a particular operator. The flat of the plunger rod 43 and the complementary opening 42A of insert 42 also insures 35 a proper orientation of the plunger pad 44 or 44A with the sternum of the patient.

While the instant invention has been described with respect to several embodiments thereof it will be readily understood and appreciated that variations and modifications may be made without departing from the spirit or scope of the invention.

What is claimed is:

1. An external heart massage apparatus comprising:

a frame means,

means for supporting said frame means so that the body of a patient is placed through said frame means,

plunger means mounted on said frame means for reciprocal movement toward and away from the body of the patient,

a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated,

a roller camming means interposed between said lever means and said plunger means through which an axial force is transmitted to said plunger means to effect reciprocal movement thereof upon displacement of said lever means,

and including:

a first stop means operatively associated with said lever means to define the minimum and maximum displacement range of said lever means and associated plunger means,

and a second stop means operatively associated with said plunger means to define limits of displacement of said plunger means intermediate of said minimum and maximum range of displacement of said plunger means.

2. An external heart massage apparatus as defined in claim 1 wherein said roller camming means includes a cam roller pivotally connected to the upper end of said plunger means whereby the periphery of said cam roller is disposed in rolling engagement with said lever means.

3. An external heart massage apparatus comprising:

a frame means,

means for supporting said frame means so that the body of a patient is placed through said frame means,

plunger means mounted on said frame means for reciprocal movement toward and away from the body of the patient,

a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated,

a roller camming means interposed between said lever means and said plunger means through which an axial force is transmitted to said plunger means to effect reciprocal movement thereof upon displacement of said lever means,

said roller camming means includes a cam roller pivotally connected to the upper end of said plunger means whereby the periphery of said cam roller is disposed in rolling engagement with said lever means,

said cam roller including a flanged guide extending laterally thereof,

and means formed on said lever means to define a guide follower for said flanged guide.

4. An external heart massage apparatus as defined in claim 3 wherein said guide follower means is defined as an elongated slot formed in said lever means for receiving said flanged guide therein to define a positive connection between said lever and said cam roller.

5. An external heart massage apparatus comprising a frame means,

means for supporting said frame means so that a body of a patient is extended through said frame means,

a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient,

a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated,

a means for limiting the stroke of said lever means,

cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means,

and means forming a positive interconnection between said lever means and said transmission means, said cam transmission means comprising:

a rocker arm pivotally connected to said plunger means, i

and said lever means having a slit formed therein for receiving said rocker arm whereby said lever means is disposed in camming relationship with said rocker arm. p

6. An external heart massage apparatus as defined in claim 5 wherein said plunger means includes:

a mounting sleeve connected to said frame means, a plunger sleeve disposed in said mounting sleeve for relative reciprocal movement relative thereto, said plunger sleeve having an upper end portion extending beyond said mounting sleeve, a spring means for biasing said plunger sleeve toward said lever means, said rocker arm being pivotally connected to the upper end portion of said plunger sleeve whereby said rocker arm is biased in rolling engagement with said lever means, a plunger rod slideably disposed with said plunger sleeve, a compression pad connected to the end of said rod adapted to engage the body of a patient, and means for adjustably securing said plunger rod in adjusted position relative to said plunger sleeve. 7. An external heart massage apparatus as defined in claim 6 and including means for pivotally connecting said compression pad to the end of said plunger rod.

8. An external heart massage apparatus as defined in claim 6 and including an adjustable stop means connected to said plunger sleeve end portion extending beyond said mounting sleeve to limit the reciprocating stroke of said plunger means intermediate the limits of said lever stroke when said lever means is actuated.

9. An external heart massage apparatus as defined in claim 5 wherein said lever means is pivoted to said frame to provide a mechanical advantage of at least 4 to 1.

10. An external heart massage apparatus as defined in claim 6 including means for keying said plunger rod to said plunger sleeve to prohibit relative rotation therebetween.

11. An external heart massage apparatus as defined in claim 5 wherein said frame means comprises an inverted, substantially U-shaped member having opposed leg portions and an interconnecting bight portion,

and said support means comprising a flat base member,

socket means connected to said base member for receiving and supporting the opposed legs of said frame means in the erected position,

and means for detachably securing said opposed legs to their respective socket means,

and said socket means and leg portion of said frame having complementary interlocking means for stowing said base member to said frame means in an inoperative, knocked-down position. 12. An external heart massage apparatus as defined in claim 11 wherein said socket means includes a cupshaped member connected to said base member,

said cup having an internal groove formed in the inner wall portion,

and said leg portion adapted to be received therein having a latching member connected to the end portion of the leg adapted to be received in said cup,

spring means for biasing said latching member toward operative latching position,

and said latching member being adapted to be received in said groove in the erected position for connecting said frame to said base member.

13. An external heart massage apparatus as defined in claim 11 wherein said socket means is recessed in the thickness of said base member,

and said cup defined thereby being formed with a circumscribing tapered lip portion to render the leg latch self-latching as said leg portion is inserted into its respective socket.

14. An external heart massage apparatus as defined in claim 11 wherein said complementary means includes means defining a hole formed in the bottom of said sockets means,

and a headed fastener connected to the leg portion of said frame whereby said base member is detachably connected to said frame by extending the headed fasteners through the holes formed in the bottom of said socket means in the stowed position of said apparatus.

15. The invention as defined in claim wherein said support means comprises:

a clamping means adapted to secure to a side rail of a stretcher means,

means defining a latching socket adapted to receive said frame means,

and means for adjustably positioning said latching socket relative to said clamping means.

16. The invention as defined in claim 15 wherein said clamping means includes:

complementary blocks and a hinge means for connecting said blocks,

said blocks being adapted to straddle a side rail of a stretcher means,

said adusting means including a slide bar slideably connected to one of said blocks for relative lateral movement,

said latching socket being mounted on said slide bar,

and means for securing said blocks in straddling relationship to a side rail.

17. The invention as defined in claim 16 and including means to limit the movement of said adjusting means relative to said blocks.

18. An external heart massage apparatus comprising:

an inverted substantially U-shaped frame having opposed leg portions and an interconnecting bight portion,

means for maintaining the bight portion of the frame over the body of a supine patient,

a plunger means supported on said bight portion,

said plunger means including a mounting sleeve con nected intermediate said bight portion,

a plunger sleeve slideably mounted within said mounting sleeve, said plunger sleeve having an upper end portion extending beyond said mounting sleeve,

a lever having one end pivotally connected to said bight portion and having its other end extending over said plunger sleeve,

a cam roller rotatably journalled to the upper end of said plunger sleeve,

said cam roller being disposed in rolling engagement with said lever,

a spring means biasing said plunger sleeve toward said lever for maintaining said cam roller in rolling engagement with said lever,

a plunger rod adjustably supported within said plunger sleeve,

means for securing said plunger rod in adjusted positlon,

a stop means connected to said frame operating on said lever to limit the displacement of said lever between a minimum and maximum displacement range, and a second stop means adjustably supported on the upper end of said plunger sleeve to limit the displacement of said plunger sleeve and plunger rod supported thereon as said lever is displaced.

19. The invention as defined in claim 18 wherein said cam roller includes a flange guide projecting radially of said cam roller,

and a guide follower means formed in said lever adapted to receive said flange guide forming a positive interconnection between said plunger means and said lever.

20. The invention as defined in claim 19 wherein said guide follower includes an elongated slot formed in said lever for accommodating said flange guide.

21. An external heart massage apparatus comprising:

a frame means,

means for supporting said frame means so that a body of a patient is extended through said frame means,

a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient,

a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated,

a means for limiting the stroke of said lever means,

cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means,

and means forming a positive interconnection between said lever means and said transmission means,

said cam transmission means comprising,

a roller mounted in the end of said plunger means whereby said roller is disposed in rolling engagement with said lever means,

and said interconnecting means including an enlarged flange guide,

and complemental slot formed on said lever means for receiving said flange guide.

22. The invention as defined in claim 21 whereby said lever limiting means includes a U-shaped bracket connected to said frame means, said lever having an end portion extended through said bracket, and said bracket having a series of spaced holes therein, and a stop pin adapted to be inserted into one of said holes to limit the stroke of said lever means.

23. An external heart massage apparatus comprising a frame means,

means for supporting said frame means so that a body of a patient is extended through said frame means,

a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient,

a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated,

a means for limiting the stroke of said lever means,

cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means,

and means forming a positive interconnection between said lever means and said transmission means,

i said means for limiting the stroke of said lever comprisa collar adjustably mounted on said plunger means,

and means for securing said collar in the adjusted position along said plunger means.

24. The invention as defined in claim 23 and including an adjusting slot vertically disposed in said plunger means, and a plurality of spaced horizontally disposed branch slots connecting with said vertical slot,

and a guide operatively connected to said collar for infinitely locating said collar along said vertical slot and at a predetermined set position in one of said horizontal slots.

25. The invention as defined in claim wherein said rocker arm includes an arcuate sector, and

said arcuate sector having a length greater than the length of said slot.

26. An external heart massage apparatus comprising a frame means,

means for supporting said frame means so that a body of a patient is extended through said frame means,

a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient,

a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated, a means for limiting the stroke of said lever means, cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means, and means forming a positive interconnection between said lever means and said transmission means, said lever means comprising a tubular member, and said cam transmission means includes a roller connected to said plunger,

and said tubular member includes a slot for receiving said roller whereby said roller is disposed within said tubular member.

27. The invention as defined in claim 5 and including a stop means for adjustably limiting the reciprocal movement of said plunger means to a distance intermediate the minimum and maximum movement of said lever.

28. The invention as defined in claim 27 wherein said stop means includes a collar slidably mounted on a plunger means,

means for prohibiting relative rotation between said collar and plunger means,

and means for fixedly securing said collar to said plunger means in the adjusted position to limit the reciprocal movement of said plunger means upon the actuation of said lever. 

1. An external heart massage apparatus comprising: a frame means, means for supporting said frame means so that the body of a patient is placed through said frame means, plunger means mounted on said frame means for reciprocal movement toward and away from the body of the patient, a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated, a roller camming means interposed between said lever means and said plunger means through which an axial force is transmitted to said plunger means to effect reciprocal movement thereof upon displacement of said lever means, and including: a first stop means operatively associated with said lever means to define the minimum and maximum displacement range of said lever means and associated plunger means, and a second stop means operatively associated with said plunger means to define limits of displacement of said plunger means intermediate of said minimum and maximum range of displacement of said plunger means.
 2. An external heart massage apparatus as defined in claim 1 wherein said roller camming means includes a cam roller pivotally connected to the upper end of said plunger means whereby the periphery of said cam roller is disposed in rolling engagement with said lever means.
 3. An external heart massage apparatus comprising: a frame means, means for supporting said frame means so that the body of a patient is placed through said frame means, plunger means mounted on said frame means for reciprocal movement toward and away from the body of the patient, a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated, a roller camming means interposed between said lever means and said plunger means through which an axial force is transmitted to said plunger means to effect reciprocal movement thereof upon displacement of said lever means, said roller camming means includes a cam roller pivotally connected to the upper end of said plunger means whereby the periphery of said cam roller is disposed in rolling engagement with said lever means, said cam roller including a flanged guide extending laterally thereof, and means formed on said lever means to define a guide follower for said flanged guide.
 4. An external heart massage apparatus as defined in claim 3 wherein said guide follower means is defined as an elongated slot formed in said lever means for receiving said flanged guide therein to define a positive connection between said lever and said cam roller.
 5. An external heart massage apparatus comprising a frame means, means for supporting said frame means so that a body of a patient is extended through said frame means, a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient, a lever means pivotally connected to said frame means and operatively associated with said plunger means for effeCting the reciprocation thereof when said lever is actuated, a means for limiting the stroke of said lever means, cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means, and means forming a positive interconnection between said lever means and said transmission means, said cam transmission means comprising: a rocker arm pivotally connected to said plunger means, and said lever means having a slit formed therein for receiving said rocker arm whereby said lever means is disposed in camming relationship with said rocker arm.
 6. An external heart massage apparatus as defined in claim 5 wherein said plunger means includes: a mounting sleeve connected to said frame means, a plunger sleeve disposed in said mounting sleeve for relative reciprocal movement relative thereto, said plunger sleeve having an upper end portion extending beyond said mounting sleeve, a spring means for biasing said plunger sleeve toward said lever means, said rocker arm being pivotally connected to the upper end portion of said plunger sleeve whereby said rocker arm is biased in rolling engagement with said lever means, a plunger rod slideably disposed with said plunger sleeve, a compression pad connected to the end of said rod adapted to engage the body of a patient, and means for adjustably securing said plunger rod in adjusted position relative to said plunger sleeve.
 7. An external heart massage apparatus as defined in claim 6 and including means for pivotally connecting said compression pad to the end of said plunger rod.
 8. An external heart massage apparatus as defined in claim 6 and including an adjustable stop means connected to said plunger sleeve end portion extending beyond said mounting sleeve to limit the reciprocating stroke of said plunger means intermediate the limits of said lever stroke when said lever means is actuated.
 9. An external heart massage apparatus as defined in claim 5 wherein said lever means is pivoted to said frame to provide a mechanical advantage of at least 4 to
 1. 10. An external heart massage apparatus as defined in claim 6 including means for keying said plunger rod to said plunger sleeve to prohibit relative rotation therebetween.
 11. An external heart massage apparatus as defined in claim 5 wherein said frame means comprises an inverted, substantially U-shaped member having opposed leg portions and an interconnecting bight portion, and said support means comprising a flat base member, socket means connected to said base member for receiving and supporting the opposed legs of said frame means in the erected position, and means for detachably securing said opposed legs to their respective socket means, and said socket means and leg portion of said frame having complementary interlocking means for stowing said base member to said frame means in an inoperative, knocked-down position.
 12. An external heart massage apparatus as defined in claim 11 wherein said socket means includes a cup-shaped member connected to said base member, said cup having an internal groove formed in the inner wall portion, and said leg portion adapted to be received therein having a latching member connected to the end portion of the leg adapted to be received in said cup, spring means for biasing said latching member toward operative latching position, and said latching member being adapted to be received in said groove in the erected position for connecting said frame to said base member.
 13. An external heart massage apparatus as defined in claim 11 wherein said socket means is recessed in the thickness of said base member, and said cup defined thereby being formed with a circumscribing tapered lip portion to render the leg latch self-latching as said leg portion is inserted into its respective socket.
 14. An external heart massage apparatus as defined in claim 11 wherein said complementary means includes means defining a hole formed in the bottom of said sockets means, and a headed fastener connected to the leg portion of said frame whereby said base member is detachably connected to said frame by extending the headed fasteners through the holes formed in the bottom of said socket means in the stowed position of said apparatus.
 15. The invention as defined in claim 5 wherein said support means comprises: a clamping means adapted to secure to a side rail of a stretcher means, means defining a latching socket adapted to receive said frame means, and means for adjustably positioning said latching socket relative to said clamping means.
 16. The invention as defined in claim 15 wherein said clamping means includes: complementary blocks and a hinge means for connecting said blocks, said blocks being adapted to straddle a side rail of a stretcher means, said adusting means including a slide bar slideably connected to one of said blocks for relative lateral movement, said latching socket being mounted on said slide bar, and means for securing said blocks in straddling relationship to a side rail.
 17. The invention as defined in claim 16 and including means to limit the movement of said adjusting means relative to said blocks.
 18. An external heart massage apparatus comprising: an inverted substantially U-shaped frame having opposed leg portions and an interconnecting bight portion, means for maintaining the bight portion of the frame over the body of a supine patient, a plunger means supported on said bight portion, said plunger means including a mounting sleeve connected intermediate said bight portion, a plunger sleeve slideably mounted within said mounting sleeve, said plunger sleeve having an upper end portion extending beyond said mounting sleeve, a lever having one end pivotally connected to said bight portion and having its other end extending over said plunger sleeve, a cam roller rotatably journalled to the upper end of said plunger sleeve, said cam roller being disposed in rolling engagement with said lever, a spring means biasing said plunger sleeve toward said lever for maintaining said cam roller in rolling engagement with said lever, a plunger rod adjustably supported within said plunger sleeve, means for securing said plunger rod in adjusted position, a stop means connected to said frame operating on said lever to limit the displacement of said lever between a minimum and maximum displacement range, and a second stop means adjustably supported on the upper end of said plunger sleeve to limit the displacement of said plunger sleeve and plunger rod supported thereon as said lever is displaced.
 19. The invention as defined in claim 18 wherein said cam roller includes a flange guide projecting radially of said cam roller, and a guide follower means formed in said lever adapted to receive said flange guide forming a positive interconnection between said plunger means and said lever.
 20. The invention as defined in claim 19 wherein said guide follower includes an elongated slot formed in said lever for accommodating said flange guide.
 21. An external heart massage apparatus comprising: a frame means, means for supporting said frame means so that a body of a patient is extended through said frame means, a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient, a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated, a means for limiting the stroke of said lever means, cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted throUgh said cam transmission means, and means forming a positive interconnection between said lever means and said transmission means, said cam transmission means comprising, a roller mounted in the end of said plunger means whereby said roller is disposed in rolling engagement with said lever means, and said interconnecting means including an enlarged flange guide, and complemental slot formed on said lever means for receiving said flange guide.
 22. The invention as defined in claim 21 whereby said lever limiting means includes a U-shaped bracket connected to said frame means, said lever having an end portion extended through said bracket, and said bracket having a series of spaced holes therein, and a stop pin adapted to be inserted into one of said holes to limit the stroke of said lever means.
 23. An external heart massage apparatus comprising a frame means, means for supporting said frame means so that a body of a patient is extended through said frame means, a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient, a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated, a means for limiting the stroke of said lever means, cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means, and means forming a positive interconnection between said lever means and said transmission means, said means for limiting the stroke of said lever comprising: a collar adjustably mounted on said plunger means, and means for securing said collar in the adjusted position along said plunger means.
 24. The invention as defined in claim 23 and including an adjusting slot vertically disposed in said plunger means, and a plurality of spaced horizontally disposed branch slots connecting with said vertical slot, and a guide operatively connected to said collar for infinitely locating said collar along said vertical slot and at a predetermined set position in one of said horizontal slots.
 25. The invention as defined in claim 5 wherein said rocker arm includes an arcuate sector, and said arcuate sector having a length greater than the length of said slot.
 26. An external heart massage apparatus comprising a frame means, means for supporting said frame means so that a body of a patient is extended through said frame means, a plunger means mounted on said frame means for reciprocal movement toward and away from the body of a patient, a lever means pivotally connected to said frame means and operatively associated with said plunger means for effecting the reciprocation thereof when said lever is actuated, a means for limiting the stroke of said lever means, cam transmission means between said lever means and said plunger whereby the force imparted between the lever means and plunger means is axially transmitted through said cam transmission means, and means forming a positive interconnection between said lever means and said transmission means, said lever means comprising a tubular member, and said cam transmission means includes a roller connected to said plunger, and said tubular member includes a slot for receiving said roller whereby said roller is disposed within said tubular member.
 27. The invention as defined in claim 5 and including a stop means for adjustably limiting the reciprocal movement of said plunger means to a distance intermediate the minimum and maximum movement of said lever.
 28. The invention as defined in claim 27 wherein said stop means includes a collar slidably mounted on a plunger means, means for prohibiting relative rotation between said collar and plunger means, and means for fixedly securing said collar to said plungEr means in the adjusted position to limit the reciprocal movement of said plunger means upon the actuation of said lever. 